Restoration of lost peer-to-peer offline transaction records

ABSTRACT

The invention provides for restoration of lost peer-to-peer offline transaction records. The lost offline transaction records may include access rights to digital media. In one embodiment, a demand for restoration of a plurality of lost peer-to-peer offline transaction records is made. In response, an attempt is made to verify each transaction for the plurality of lost transaction records. This attempt is made through another party to the corresponding transaction. An accuracy indicator is assigned to each transaction to indicate whether the transaction is verified directly through another party to the corresponding transaction. A determination is made as to whether each transaction record of the plurality of lost transaction records should be restored based on the assigned accuracy indicators.

FIELD OF THE INVENTION

The present invention relates to the field of peer-to-peer networks and,more particularly, to restoration of lost peer-to-peer transactionrecords.

BACKGROUND OF THE INVENTION

Music and video content is increasingly being distributed via theInternet. Recent advances in audio and video compression, higherbandwidth Internet connections, and the decreasing cost of memory havemade it practical for users to download audio and video content via theInternet to personal computers and other dedicated digital devices. Thedownloaded content can also be transferred to compact disks (CDs),mini-disks or digital video disks and played on other audio and videodevices such as MP3-format digital players. MP3 (MPEG Audio Layer 3)format is a compression system for digital music that helps reduce thesize of a digitized song without significantly degrading the soundquality.

Digital music converted to MP3 format is currently available on theWorld Wide Web for individual use. MP3 files can be downloaded from theInternet using a computer and special software. Furthermore, a personalcomputer programmed with appropriate software can convert digital musicfrom a CD to MP3 format. Currently, MP3 files can be played in differentways: an MP3 file can be played directly on a personal computer; an MP3file can be decompressed and recorded onto CD; and an MP3 file can beplayed on an MP3 player. MP3 players are relatively small, lightweight,portable devices that can interface with a personal computer. Thus, auser can download MP3 files from the Internet and load such MP3 filesonto the MP3 player. Typically, the MP3 player can be connected to apersonal computer's parallel or USB port in order to receive thedownloaded MP3 files.

The practice of downloading media from the Internet, particularly music,has been the source of much controversy. Peer-to-peer software such asNapster, Morpheus and Kaza has been utilized to provide consumers withthe ability to freely share copyrighted digital media. In a sense, suchsoftware makes it possible for consumers to arguably commit intellectualproperty theft with relative ease. As a result, consumers have little orno motivation to go a record store and purchase CDs, albums or the likewhen they can simply download the desired music via a web site. Needlessto say, media providers, as well as creators of the music, are opposedto such practices since they do not receive any financial compensationwhen the copyrighted digital media is downloaded and transferred betweenusers.

Accordingly, what is needed are techniques for addressing problemsrelated to the peer-to-peer transaction of digital media. It is towardthese ends that the present invention is directed.

SUMMARY OF THE INVENTION

The invention provides for restoration of lost peer-to-peer offlinetransaction records. The lost transaction records may include accessrights to digital media. In one embodiment, a demand for restoration ofa plurality of lost peer-to-peer transaction records is made. Inresponse, an attempt is made to verify each transaction for theplurality of lost transaction records. This attempt is made throughanother party to the corresponding transaction. An accuracy indicator isassigned to each transaction to indicate whether the transaction isverified directly through another party to the correspondingtransaction. A determination is made as to whether each transactionrecord of the plurality of lost transaction records should be restoredbased on the assigned accuracy indicators.

These and other aspects of the present invention are described in moredetail herein.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates a peer-to-peer network in which the present inventionmay be implemented;

FIG. 2 illustrates a media card by which the present invention may beimplemented;

FIG. 3 illustrates a transaction log in accordance with an embodiment ofthe present invention;

FIG. 4 illustrates a flowchart of a method for restoring losttransaction records in accordance with an embodiment of the presentinvention; and

FIG. 5 illustrates a flowchart of an alternate method for restoring losttransaction records in accordance with an embodiment of the presentinvention.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT

The invention provides for restoration of lost peer-to-peer transactionrecords. The invention is particularly useful where rights to accesscontent are received from a content provider, transferred in an onlineor offline manner among peers in exchange for tokens representinglicense fees and electronically stored. For example, the access rightsmay be stored as transaction records in a portable device, such as asmart card. In the event of a loss of the records, e.g., where theportable device fails or is lost, it would be desired to restore thetransaction records without the party having to re-purchase the rightsfor which tokens had already been exchanged. Such a system is describedin U.S. application Ser. No. 10/428,810, filed May 1, 2003, stillpending the entire contents of which are hereby incorporated byreference. The lost transaction records may include access rights todigital media.

In one embodiment, a demand for restoration of a plurality of lostpeer-to-peer transaction records is made. In response, an attempt ismade to verify each transaction for the plurality of lost transactionrecords. This attempt is made through another party to the correspondingtransaction. An accuracy indicator is assigned to each transaction toindicate whether the transaction is verified directly through anotherparty to the corresponding transaction. A determination is made as towhether each transaction record of the plurality of lost transactionrecords should be restored based on the assigned accuracy indicators.

Selected ones of the lost transaction records may then be restored.Restoration may only be of those transaction records that are verifieddirectly. At least one of the lost transaction records may be restoredbefore the transaction is verified through the other party to thetransaction. A log of transaction records may be received from eachother party to the transactions for the lost transaction records whoserecord of the transaction is not lost; verification of the transactionrecords is based on the received logs.

The accuracy indicator may further indicate whether the transactionrecord for a transaction is verified indirectly through another party tothe corresponding transaction and, if so, the accuracy indicator mayalso indicate the number of parties through which the transaction isverified indirectly. Restoration may be only of those transactionrecords that are verified directly and those that are verifiedindirectly through one other party.

The determination of whether to restore lost transaction records may befurther based on a history for the party making the demand. The historyfor the party may indicate verified and unverified transactions. Thehistory for the party may include a ratio of a number of verifiedtransactions to a number of lost transactions. When the ratio exceeds athreshold, at least one of the lost transaction records may be restoredbefore the transaction is verified through the other party to thetransaction. The party may be blacklisted when the number of unverifiedtransactions exceeds a threshold. When the party is blacklisted, onlythose transaction records that are verified directly may be restored.

FIG. 1 illustrates a peer-to-peer network in which the present inventionmay be implemented. As shown in FIG. 1, one or more content providers102 may be accessible via a wide area network (WAN) 104, such as theInternet. A number of peer devices 106 may access the WAN 104 or otherpeer devices 106 via local connections 108. Thus, a peer device 106 maypurchase access rights to content from a content provider 102 andtransfer the access rights to another peer device 106. While not shown,intermediate servers, referred to as “hot spots” may provide aninterface between the content providers 102 and the peer devices 106. Itwill be apparent that other modifications may be made to the network.

An access right can be considered a license to use to the correspondingcontent. The access rights may be transferred to a among the peerdevices 106 by the exchange of tokens, which represent monetary value,and the access rights, e.g., in the form of a password or decryptionkey, that enables use of the licensed content.

In an embodiment, the peer devices 106 include media cards thatincorporate smart card technology. Generally speaking, smart cards arewallet-sized (or smaller) cards incorporating a microprocessor ormicrocontroller to store and manage data within the card. More complexthan magnetic-stripe and stored-value cards, smart cards generallyinclude memory management and security features. Multi-function cards,for example, are often configured to support credit, debit, storedvalue, loyalty, and a number of other applications all within a singlecard. A typical multi-function smart card includes a microcontrollerembedded within the card plastic which is electrically connected to anarray of external contacts provided on the card exterior.

The smart card microcontroller generally includes anelectrically-erasable and programmable read only memory (EEPROM) forstoring user data, random access memory (RAM) for scratch storage, andread only memory (ROM) for storing the card operating system. Relativelysimple microcontrollers are generally adequate to control thesefunctions. Thus, it is not unusual for smart cards to utilize 8-bit, 5MHZ microcontrollers with about 8K of EEPROM memory (for example, theMotorola 6805 or Intel 8051 microcontrollers).

A number of standards have been developed to address various aspects ofsmart cards, e.g.: ISO 7816-1, Part 1: Physical characteristics (1987);ISO 7816-2, Part 2: Dimensions and location of the contacts (1988); ISO7816-3, Part 3: Electronic signals and transmission protocols (1989,Amd. 1 1992, Amd. 2 1994); ISO 7816-4, Part 4: Interindustry commandsfor interchange (1995); ISO 7816-5, Part 5: Numbering system andregistration procedure for application identifiers (1994, Amd. 1 1995);ISO/IEC DIS 7816-6, Inter-industry data elements (1995); ISO/IEC WD7816-7, Part 7: Enhanced inter-industry commands (1995); and ISO/IEC WD7816-8, Part 8: Inter-industry security architecture (1995). Thesestandards are hereby incorporated by reference.

FIG. 2 illustrates a media card device that could be utilized inconjunction with a method in accordance with an embodiment of thepresent invention. The media card may serve as a peer device 106(FIG. 1) and includes a central processing unit 202 (CPU) which isconnected to a read only memory 204 (ROM), primarily used for storage ofan operating system. A random access memory 206 (RAM) is also providedfor volatile storage of data, particularly for program execution. TheCPU 202 is operatively coupled to a serial interface 208 that in turncommunicates with a card reader 210 according to techniques well knownin the art.

The CPU 202 is connected to an arithmetic logic unit 210, for example,one suitable for processing large keys (512 byte keys, 1024 currentRSA). An electrically erasable programmable read only memory 212(EEPROM) is provided, which typically stores system files andapplications. The media card could be a Compaq flash card or memorystick.

In an embodiment of the present invention, the media card is obtained(usually purchased) by a user and is utilized to obtain access rightsfor different types of media. For the purposes of this patentapplication, an access right can be thought of as a pseudo-license touse the associated media. These access rights can be purchased with themedia card whereby the media card is subsequently used in conjunctionwith a media-playing device to access the media. For example, at thetime the user purchases the media card, the user can also purchase anumber of digital tokens or any other medium of exchange, which can belater used to purchase access rights to media. For the purposes ofidentifying/authenticating users of media cards, a unique digitalcertificate can be stored into the card for the purpose ofauthenticating/identifying a user. Additionally, for an added securitymeasure, a requirement could be established whereby the certificateshave to be renewed after a predetermined amount of time (once a month,once a quarter, etc.) or after a predetermined number of transactions.

Once a media card device acquires the access rights to a particularmedia content, the media card can be used in conjunction with amedia-playing device to play the selected media. For example, if thepurchased media is a particular song, the media card can be insertedinto a reader 210 of a juke box and the user will be able to play theparticular song. In an alternate embodiment, the media card can beutilized to play the media via a separate media-playing device such asan MP3 player.

Furthermore, to make it possible to perform offline transactions, thatis transactions made disconnected from the Internet infrastructure, atransaction log is maintained on the media card (e.g., in memory 212)whereby each transaction made offline with the media card is recordedand stored in a local file. Accordingly, a user can defer the payment ofthe fee to the provider of the media when he performs an offlinetransaction. When this user attempts to renew the card, i.e. renew theunique certificate, the system will check his transaction log and askhim to pay for his transactions made offline. If the transactions arepre-paid by advance purchase of tokens the system may check theremaining number of tokens and offer to sell additional ones. Thus, eachuser is required to periodically upload their transaction log to thecontent provider 102 (FIG. 1).

FIG. 3 illustrates an exemplary transaction log 300 in accordance withan embodiment of the present invention. Each peer device 106 has its owntransaction log 300 which represents a history of transactions it hasparticipated in. The transaction log includes a record of eachtransaction by which access rights have been transferred to or from thecorresponding peer device 106 (FIG. 1).

As shown in FIG. 3, each record may occupy a row in the log 300 and mayinclude: a transaction identifier (e.g., a unique number assigned toeach transaction); a transaction type, which specifies whether the mediacontent was purchased or sold by the peer device 106 for the log 300; amedia identifier, which identifies the particular media (e.g., aparticular song); a transacting party identifier, which identifies theother party to transaction (i.e. the party from whom access rights werepurchased or to whom access rights were sold); and an access key, whichallows the corresponding content to be accessed. It will be apparentthat the arrangement of elements of the transaction log is exemplary andthat items can be omitted or added. For example, the log 300 may alsoinclude a purchase price (e.g., in tokens) for the transaction.

Occasionally, a peer device 106 (e.g., a media card) may fail. Forexample, a hardware failure of a media card may render the deviceinoperable. Further, a peer device 106 may be lost or stolen. In eithercase, the transaction log 300 is lost. If offline transactions haveoccurred since the transaction log 300 has been uploaded, the contentprovider 102 will not have received a record of those transactions fromthe device that would enable to content provider 102 to restore theaccess rights to the user. However, the user will have expended tokensto acquire the access rights. This presents a problem in that it wouldbe desirable to only restore those access rights that the user hasactually purchased. In addition, in the case of sales, it would bedesirable to restore any commissions due to a seller if the seller'stransaction log is lost.

Thus, the invention provides for restoration of lost peer-to-peertransaction records. This is accomplished based on the circumstance thatwhile performing transactions, a user interacts with other users. When auser loses their peer device 196 (which may be media card) or it fails,portion of the log of those transactions remain on the media cards ofthe other users with whom the transactions were made. This informationcan generally be used to reconstitute at least portions of the user'stransaction log.

For example, assume that a user U purchases some media content. User Ubuys content C1 from user U1, content C2 from user U2 and content C3from the user U3. Then user U loses their media card. User U contactsthe content provider and makes a demand for restoration of the mediacontents: “I lost the contents C1, C2 and C3—can you please give me themback?”

In response, the content provider may give those contents (by providingthe corresponding access rights to the user U without charging anyadditional fees. But it records this “gift” in its files. At some time,each of the users U1, U2 and U3 will upload their transaction logs tothe content provider, for example, by visiting a point-of-sale location.The content provider may then verify from those transaction logs thatthe users U1, U2 and U3 performed transactions with user U that matchthe claim of user U.

Content provider may then retain of record of whether the claimedtransactions can be verified or not for future use should the user makea claim in the future. This record is an indicator of the accuracy ofthe user's claims. For example, if the accuracy indicator indicates thatthe user's previous claims had a high degree of accuracy, the contentprovider may be more likely to provide requested content before atransaction of a current claim can be verified by the transaction log ofanother user or when the transaction cannot be so verified.

FIG. 4 illustrates a flowchart of a method 400 for restoring losttransaction records in accordance with an embodiment of the presentinvention. The method 400 may be performed at a content provider 102(FIG. 1) and may be performed by a general purpose computer thatoperates in accordance with a stored software program that controls thecomputer to perform the steps of the method. Alternately, the method 400may be performed by special purpose hardware and/or firmware may alsoinclude portions that are performed by human operators. For example, adecision as to whether to restore a particular transaction may beinitially made according to the stored software program and thenforwarded to a human operator for a final determination.

In a step 402 a determination is made as to whether to restore requestedcontent. As mentioned, this determination may be based at least in parton the past history of the user making the request. In step 404, theselected transactions are restored according to the determination madein step 402. For example, if the determination of step 402 is to restoreonly certain ones of the claimed transactions, then the correspondingaccess rights are restored in step 404. In step 406, an attempt is madeto verify the transactions. As mentioned, this may be accomplished bythe content provider checking the logs of user's with whom the usermaking the claim has participated in the transactions. In step 408, anaccuracy indicator is assigned to the claimed transactions. Asmentioned, this may be used for making determinations (step 402) forfuture transactions.

Note that it is not necessary for these steps to be performed in theorder shown in FIG. 4. For example, recall that other users that engagein transactions with the user U who is making the request periodicallyupload their transaction logs. If some or all of the users have done sobefore the user U makes the claim, then those transactions may beimmediately verified.

FIG. 5 illustrates a flowchart of an alternate method 500 for restoringlost transaction records in accordance with an embodiment of the presentinvention. In step 502, an attempt is made to verify the transactions.As mentioned, this may be accomplished by the content provider checkingthe logs of user's with whom the user making the claim has participatedin the transactions. Then, in step 504, an accuracy indicator isassigned to the claimed transactions. Here, the accuracy indicator isbased at least in part on results of the step 502. In a step 506 adetermination as to whether to restore requested content is made. Thisdetermination may be based at least in part on the accuracy indicatorassigned in step 504, but may also be based on the past history) of theuser making the request, e.g., by taking into account accuracyindicators of prior requests. In step 508, the selected transactions arerestored according to the determination made in step 506.

In certain circumstances, the user U may have engaged in transactionswith other users who have also lost their transaction log. Returning tothe example in which user U buys content C1 from user U1, content C2from user U2 and content C3 from the user U3, assume that the user U3has also lost their transaction log (e.g., because user U3 has losttheir media card or it has failed). However, assume also that the userU3 bought the content C3 from user U4 before selling it to the user U,that U4's transaction log can be found and that user U4's transactionlog shows that U3 did, indeed, purchase the content C3. This means thatthe claim of the user U that it purchased the content C3 from the userU3 is plausible (i.e. it cannot be refuted) though the transactioncannot be verified directly by U3's transaction log. This referred to anindirect verification. In other words, the claim of the user U that theypurchased access rights to the content C3 can be indirectly verified bythe transaction log of the user U4.

Conversely, assume that U4's transaction log shows that U3 did notpurchase the content C3 at a time that would have made it possible for Uto have purchased the content C3 from the user U3. In this case, theuser U's claim with respect to the transaction can be refuted asincorrect. Thus, indirect verification is based on the premise that theaccess rights acquired by each user comes from somewhere: either fromthe content provider itself, or from another user.

Where a transaction can be verified directly, an accuracy indicator ofzero (“0”) may be assigned to the transaction. Where a transaction canonly be verified indirectly through one other user, as in the exampleabove, an accuracy indicator of one (“1”) may be assigned to thetransaction. Assume, in the example above, that the user U4 had alsolost their transaction log, that the user U3 had made a claim that theyhad purchased the content C3 from the user U4 and that the user U5'stransaction log indicates that the user U4 had purchased the content C3from the user U5 prior to the claimed transactions of the users U3 andU4. In this case, an accuracy indicator of two (“2”) may be assigned tothe transaction to indicate that the claim of the user U can only beverified indirectly though two other users (i.e. users U3 and U4).Similarly, accuracy factors of 3, 4, 5, etc. can be assigned where atransaction can only be indirectly verified through a correspondingnumber of other users.

Where a transaction is refuted, an accuracy indicator of “refuted” maybe assigned to the transaction. Further, where the information needed toverify a transaction is not yet available an accuracy indicator of“pending” may be assigned to the transaction. In the example, where anattempt is being made to verify a purchase by the user U from the userU3 and the user U3 has not recently uploaded their transaction log, anindicator of “pending” may be assigned to the transaction until the userU3 is heard from (e.g., they upload their transaction log or make aclaim that they, too, have lost their media card). Thus, “pending” and“refuted” transactions are unverified, in contrast to transactions thatare verified directly or indirectly.

Table 1 shows an example of accuracy indicators being assigned to eachof several claims for lost transactions made by a user:

TABLE 1 Claimed Lost Content Assigned Accuracy Indicator C1 1 C2 0 C3 0C4 refuted C5 1 C6 3 C7 1 C8 pending

For each transaction, a decision may be made as to whether to restorethe content according to a predetermined policy, for example: (i)restore all content whose accuracy factor is 0; (ii) restore all contentwhose accuracy factor is 1 or greater or pending, only if the user isnot black-listed; and (iii) if a number of claims (e.g., two or more)are proven wrong (refuted), then the user is black-listed. As anotherexample, the policy may be as follows: (i) restore all content whoseaccuracy factor is 0 or 1; and (ii) restore all content whose accuracyfactor is greater than 1 or pending, only if the user is notblack-listed; and (iii) if two or more claims are proven wrong(refuted), then the user is black-listed. It will be apparent thatdifferent policies may be used.

The above examples in which a claim is indirectly verified require thatthe user making the claim be able to identify from whom the content wasobtained. Thus, in order to be able to indirectly verify U's claim thatcontent C3 was purchased from U3 where U3 transaction log is lost (i.e.by examining U4's transaction log to see that it sold the content toU3), the user U must be able identify U3 as the seller. In certaincircumstances, the user U making a request for restoration of lostcontent may not be able to identify the other party to each transaction.

In this case, the method 500 of FIG. 5 may be performed. In step 502, anattempt is made to verify those transactions for which the user cannotidentify the other party by checking transaction logs uploaded by otherparties to see if any reported a matching transaction with the usermaking the claim. If so, an accuracy indicator of “0” may be applied tothe transaction. For example, assume the transaction log of the user Uis lost and the user U claims that they purchased content C3, but cannotremember from whom. Assume that the user U3 had uploaded theirtransaction log which indicates that the user U purchased the content C3from the user U3. This directly verifies U's claim as to thattransaction.

Then, in step 504, considering all the claims of user U1, a ratio of thenumber of claims verified as plausible with an accuracy factor “0” tothe total number of transactions claimed can be calculated:R=(number of claims plausible with an accuracy factor of zero)/(totalnumber of claims)

In step 506, it may be decided whether to restore selected transactionsbased on the value of R. For example, a policy may be to trust theclaims of the U if this ratio is above a certain predetermined valueRmin, for example 50% (half of the claims of user U can be verified, sowe trust the user U). Further, past behavior of the user can be used todetermine the level of trust given to U. For example, if U1 loses hismedia card a second time, Rmin can be increased to 75% and to 95% thethird time. The level of Rmin may be adjusted to be lower than itotherwise would be where a user had a high level of R for a prior claim.Where the value of R is less than Rmin, only those transactions that canbe directly verified may be restored.

While the foregoing has been with reference to particular embodiments ofthe invention, it will be appreciated by those skilled in the art thatchanges in these embodiments may be made without departing from theprinciples and spirit of the invention, the scope of which is defined bythe appended claims.

1. A method of responding to a demand for restoration of lost offlinepeer-to-peer transaction records comprising: a content provider grantingaccess rights to content; engaging in transactions involving the accessrights among peer devices while offline the content provider; attemptingto verify the transactions for a plurality of lost transaction recordshaving been lost by a party to the transactions, through the peer deviceof another party to each of the corresponding transactions; assigning anaccuracy indicator to transactions of the plurality of lost transactionrecords wherein the accuracy indicator indicates whether the transactionis verified directly through another party to the correspondingtransaction; and determining whether transaction records of theplurality should be restored based on the assigned accuracy indicators.2. The method according to claim 1, wherein said lost transactionrecords include access rights to digital media.
 3. The method accordingto claim 1, further comprising restoring selected ones of the losttransaction records.
 4. The method according to claim 3, wherein saidrestoring comprises restoring only those transaction records that areverified directly.
 5. The method according to claim 3, wherein saidrestoring comprises restoring at least one of the lost transactionrecords before the transaction is verified through the other party tothe transaction.
 6. The method according to claim 3, wherein saiddetermining comprises receiving a log of transaction records from eachother party to the transactions for the lost transaction records whoserecord of the transaction is not lost.
 7. The method according to claim6, wherein the accuracy indicator further indicates whether thetransaction record for a transaction is verified indirectly throughanother party to the corresponding transaction.
 8. The method accordingto claim 7, wherein the accuracy indicator indicates the number ofparties through which the transaction is verified indirectly.
 9. Themethod according to claim 7, wherein said restoring comprises restoringonly those transaction records that are verified directly and those thatare verified indirectly through one other party.
 10. A method ofresponding to a demand for restoration of lost offline peer-to-peertransaction records comprising: attempting to verify transactions for aplurality of lost transaction records through another party to thecorresponding transaction, wherein said lost transaction records includeaccess rights to digital media; assigning an accuracy indicator totransactions of the plurality of lost transaction records wherein theaccuracy indicator indicates whether the transaction is verifieddirectly through another party to the corresponding transaction;determining whether transaction records of the plurality should berestored based on the assigned accuracy indicators, wherein saiddetermining is performed based on a ratio of a number of verifiedtransactions to a number of lost transactions; and restoring selectedones of the lost transaction records.
 11. The method according to claim10, wherein when the ratio exceeds a threshold, said restoring comprisesrestoring at least one of the lost transaction records before thetransaction is verified through the other party to the transaction. 12.The method according to claim 10, wherein the ratio is of directlyverified transactions to a number of lost transactions and when theratio exceeds a threshold, said restoring comprises restoring at leastone transaction that is not directly verified.
 13. A method ofresponding to a demand for restoration of lost offline peer-to-peertransaction records comprising: attempting to verify transactions for aplurality of lost transaction records through another party to thecorresponding transaction, wherein said lost transaction records includeaccess rights to digital media; assigning an accuracy indicator totransactions of plurality of lost transaction records wherein theaccuracy indicator indicates whether the transaction is verifieddirectly through another party to the corresponding transaction;determining whether transaction records of the plurality should berestored based on the assigned accuracy indicators, wherein saiddetermining is further based on a history for the party making thedemand; and restoring selected ones of the lost transaction records. 14.The method according to claim 13, wherein the history for the partyindicates whether the party has made one or more previous demands forrestoration of lost transaction records.
 15. The method according toclaim 13, wherein the history the party indicates verified andunverified transactions.
 16. The method according to claim 15, whereinthe unverified transactions include refuted transactions.
 17. The methodaccording to claim 15, wherein the unverified transactions includetransactions for which a transaction log of another party to thetransaction is unavailable.
 18. The method according to claim 13,wherein the history for the party includes a ratio of a number ofverified transactions to a number of lost transactions.
 19. The methodaccording to claim 18, wherein when the ratio exceeds a threshold, saidrestoring comprises restoring at least one of the lost transactionrecords before the transaction is verified through the other party tothe transaction.
 20. The method according to claim 18, wherein the ratiois of directly verified transactions to a number of lost transactionsand when the ratio exceeds a threshold, said restoring comprisesrestoring at least one transaction that is not directly verified. 21.The method according to claim 15, wherein the party is blacklisted whenthe number of unverified transactions exceeds a threshold.
 22. Themethod according to claim 21, wherein when the party is blacklisted,said restoring comprises restoring only those transaction records thatare verified directly.
 23. A content provider for responding to a demandfor restoration of lost transaction records wherein the content providerreceives a demand for restoration of lost peer-to-peer transactionrecords having been lost by a party to the transactions and thetransactions involving access rights to content transacted among peerdevices while offline from a content provider, the content providerhaving granted the access rights to the content, and wherein the contentprovider assigns an accuracy indicator to transactions of the pluralityof lost transaction records based on attempts to verify transactionsthrough the peer device of another party to each of the correspondingtransactions, and determines whether to restore selected ones of thelost transaction records based on the assigned accuracy indicators. 24.A program storage device readable by a machine, tangibly embodying aprogram of instructions executable by the machine to perform methodsteps for responding to a demand for restoration of lost peer-to-peertransaction records comprising: receiving a demand for restoration oflost peer-to-peer transaction records having been lost by a party to thetransactions and the transactions involving access rights to contenttransacted among peer devices while offline from a content provider, thecontent provider having granted the access rights to the content;attempting to verify transactions for a plurality of lost transactionrecords through the peer device of another party to each of thecorresponding transactions; assigning an accuracy indicator totransactions of the plurality of lost transaction records wherein theaccuracy indicator indicates whether the transaction is verifieddirectly through another party to the corresponding transaction; anddetermining whether transaction records of the plurality should berestored based on the assigned accuracy indicators.
 25. The programstorage device according to claim 24, wherein said lost transactionrecords include access rights to digital media.
 26. The program storagedevice according to claim 24, the method steps further comprisingrestoring selected ones of the lost transaction records.
 27. The programstorage device according to claim 26, wherein said determining isperformed based on a ratio of a number of verified transactions to anumber or lost transactions.
 28. The program storage device according toclaim 26, wherein said determining is further based on a history for theparty making the demand.